4.4-stable review patch. If anyone has any objections, please let me know.
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From: Julian Wiedmann jwi@linux.ibm.com
commit 64e03ff72623b8c2ea89ca3cb660094e019ed4ae upstream.
When allocating a new AOB fails, handle_outbound() is still capable of transmitting the selected buffer (just without async completion).
But if a previous transfer on this queue slot used async completion, its sbal_state flags field is still set to QDIO_OUTBUF_STATE_FLAG_PENDING. So when the upper layer driver sees this stale flag, it expects an async completion that never happens.
Fix this by unconditionally clearing the flags field.
Fixes: 104ea556ee7f ("qdio: support asynchronous delivery of storage blocks") Cc: stable@vger.kernel.org #v3.2+ Signed-off-by: Julian Wiedmann jwi@linux.ibm.com Signed-off-by: Martin Schwidefsky schwidefsky@de.ibm.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- arch/s390/include/asm/qdio.h | 1 - drivers/s390/cio/qdio_main.c | 5 ++--- 2 files changed, 2 insertions(+), 4 deletions(-)
--- a/arch/s390/include/asm/qdio.h +++ b/arch/s390/include/asm/qdio.h @@ -261,7 +261,6 @@ struct qdio_outbuf_state { void *user; };
-#define QDIO_OUTBUF_STATE_FLAG_NONE 0x00 #define QDIO_OUTBUF_STATE_FLAG_PENDING 0x01
#define CHSC_AC1_INITIATE_INPUTQ 0x80 --- a/drivers/s390/cio/qdio_main.c +++ b/drivers/s390/cio/qdio_main.c @@ -640,21 +640,20 @@ static inline unsigned long qdio_aob_for unsigned long phys_aob = 0;
if (!q->use_cq) - goto out; + return 0;
if (!q->aobs[bufnr]) { struct qaob *aob = qdio_allocate_aob(); q->aobs[bufnr] = aob; } if (q->aobs[bufnr]) { - q->sbal_state[bufnr].flags = QDIO_OUTBUF_STATE_FLAG_NONE; q->sbal_state[bufnr].aob = q->aobs[bufnr]; q->aobs[bufnr]->user1 = (u64) q->sbal_state[bufnr].user; phys_aob = virt_to_phys(q->aobs[bufnr]); WARN_ON_ONCE(phys_aob & 0xFF); }
-out: + q->sbal_state[bufnr].flags = 0; return phys_aob; }